In this talk I will show our lattice calculations of the shear viscosity and bulk viscosity in the quenched approximation at $1.5T_c$. The viscosities are extracted via a Kubo formula from the reconstructed spectral function embedded in the the corresponding channels of the energy-momentum tensor correlators. We obtain unprecedented precision for the correlators by applying gradient flow and blocking methods. The correlators are extrapolated to the continuum and then to zero flow time. To extract the viscosities we fit theoretically inspired models to the lattice data and crosscheck the fit results using the Backus Gilbert method.